Mathematical modeling is a field of interest to various researchers working in various disciplines of Mathematical, Social, Psychological, Environmental, and Life Sciences. These mathematical models deal with both types of uncertainties arising on account of probabilistic as well as fuzzy distributions and find tremendous applications to a variety of disciplines. Keeping in view the idea, we have developed many uncertain models dealing with probability distributions and fuzzy distributions. The present book is basically concerned with the study of entropy function which is a notion of disorder or chaos, uncertainty or randomness. It was introduced by Clausius in the 19th century in thermodynamics and was an integral part of Boltzmann’s theory. The present volume will be a source of inspiration and help to information theoreticians and computer programmers and will also serve as a source of ready reference for the scientific community.